A. Related Applications
There are no applications for patent related hereto heretofore filed in this or any foreign country.
B. Field of Invention
This invention relates generally to weighted downriggers for troll fishing and more particularly to such a downrigger having a vertical stabilizing fin with means to attract fish and a leveraged line holding clamp.
C. Description of the Prior Art.
In troll-type fishing it commonly is necessary to maintain a fishing lure at substantial depths beneath the surface of a body of water to effectively catch fish. Commonly with most smaller game fish, it is not feasible to maintain sufficient weight on a fishing line itself to establish a lure at appropriate depths because of the quite substantial drag of both the fishing line and weighting elements in moving through water, especially when considered in comparison to the size of a fish to be caught and the forces that might be created on a fishing line by that fish. Responsive to this problem so-called "downriggers have come into use to maintain fishing lines at appropriate depths without disrupting other fishing processes.
These downriggers are suspended by a downrigger line, separate from a fishing line and carried by a support structure on a boat. This type of downrigger suspension eliminates the problem of downrigger drag on a fishing line, as that force is carried by the downrigger line. With such downriggers, an associated fishing line is fastened to the downrigger by some type of releaseable clamp that holds the fishing line spacedly inwardly adjacent a lure. Such fishing line clamps are releasable upon appropriate force being exerted upon either end of a fishing line passing away from the clamp. Our invention provides an improved downrigger of this type.
Traditional downriggers of the prior art have generally not been concerned with features other than sufficient weight to serve their purpose. Such downriggers are not of particularly streamlined shape and often do not provide suspension lines that minimize water resistance, both of which result in substantial drag forces when the downrigger moves through water. Additionally such downriggers have not been stable in maintaining a uniform course in moving through water, but rather have been erratic and often moved in an undulating course, particularly in a horizontal direction.
Such prior downriggers have often had sufficient drag that with normal weight, they are not maintained beneath a supporting boat during trolling activities, but rather trail substantially rearwardly of a boat. This is not desirable as many fishermen that use downriggers also use display type depth-finding devices, and it is preferred that a downrigger be observable by such devices. Excessive drag may, if it exists, move a downrigger out of the cone observed by depth finders.
Our invention seeks to solve these problems by providing a downrigger that has a high density body with a streamlined shape and an oblately hemispherical nose to aid passage through water at the relevant speeds to reduce drag. Additionally, we provide a relatively low density vertical fin of substantial area extending rearwardly from the body to aid stabilization. We use a suspension line of small cross-section for the strengths required. These features tend to provide a downrigger that upon motion through water remains nearly vertically beneath its point of suspension and maintains a relatively stable and uniform course of passage through the water.
Known downriggers have generally been concerned only with their weighting function and have not provided any means to attract fish to increase the probability of those fish finding a lure associated with the downrigger. Our downrigger provides both optical and audio-like fish attractants. The stabilizing fin has surfaces formed of highly light reflective materials, such as are often used on fishing lures, so that the fin is highly visible to fish. The substantial area of the stabilizing fin and its motion through water both aid to enhance this feature. Additionally, we provide a rotating propeller in the medial portion of the stabilizing fin. This propeller also has surfaces that are formed of highly light reflective materials and may be colored to provide potential optical attractiveness of the device. These features are further enhanced by rotary motion of the porpeller which tends to move the reflective surfaces at different angles to a light source to produce a complex reflective pattern of continuously changing nature.
Additionally, the propeller provides an "acoustical" attractant for fish in generating fish sensible pressure waves in the water through which it passes by causing cavitation, motion or otherwise. Fish are more attracted to the vicinity of our downrigger than they are to the vicinity of downriggers not having these features, apparently by reason of the curiosity of the fish and their instinctual behavior associating bright, shiny surfaces and pressure disturbances with food.
Our invention provides a clamp-type line holding device that has lever means to multiply the force on the lure end of a line to cause release of the clip, while the clamp yet requires a substantially larger force on the supported or inboard end of the line to cause release. Line clamping devices of known downriggers traditionally have provided two clamping surfaces biased in surface adjacency, but movable against their bias to release a line carried therebetween. With such clamping devices the same force on either end of a line being held by such clamp will release the line. If a relatively small fish were caught by a lure on a fishing line held in such a clamp, the force that fish might exert upon the line oftentimes was not sufficient to cause the clamp to release. Many such prior clamps allowed adjustment of the required clamp release force, by but the drag of a line extending between fishing line support and a clamp was so large that that drag necessarily determined the lowest amount of force that could be allowed to release the clamp. Such line drag force often was substantially greater than the force caused by a small fish hooked on a lure, so that if a small fish were caught, it would not release the clamp, but rather would be dragged behind the downrigger with no knowledge of a fisherman that it had been caught.
Our invention provides a lever arm, extending from one jaw of an adjustable clamp, that carries a fishing line extending to a lure. The length of this lever arm allows the force exerted on a lure to be magnified in its action on the clamp jaw carrying it so that a fishing line will be released by small forces caused by a small fish that are less than the line drag force. The lever arm of our clamp may be releasably positionable to allow the use of interchangeable lever arms of different legths with the same clamp jaw to provide different leverage advantages.
Our invention resides not in any one of these features per se, but rather in the synergistic combination of all of them to provide the structures and the functions necessarily flowing therefrom, as herein specified and claimed.